1. These numbers represent different
units of count, and this analysis should
not be interpreted as suggesting that
exactly 62 percent of all arrested youth
were referred to juvenile courts in 1997.
Changes in the relationship between juvenile
arrests and juvenile court cases, however,
do indicate law enforcement’s shifting
emphasis on court referral.

2. This example is intended as a demonstration
of projection methodology and
not an analysis of national custody populations
that could be used to formulate
State or Federal policy. For this reason,
all data, including population counts, are
rounded.

3. The juvenile custody population numbers
in table 1 are drawn from the Census
of Juveniles in Residential Placement
(CJRP) in 1997 and from the Census of
Public and Private Juvenile Detention,
Correctional, and Shelter Facilities, also
known as the Children in Custody (CIC)
census, in the years prior to 1997. CJRP
differs fundamentally from CIC, which collected
aggregate data on juveniles held in
each facility. CJRP collects individual data
on each juvenile held in each residential
facility in the census. Since there was a
change in data collection instruments, it
is difficult to determine how much of the
increase in the number of delinquents in
custody is real and how much is due to
the change in methods. According to
OJJDP (see Snyder and Sickmund, 1999),
the “roster” format of the CJRP data,
along with electronic reporting, may have
facilitated a more complete accounting of
juveniles in facilities. In the years when
CIC was used, there were many private
facilities that did not report juveniles
in custody. It is therefore likely that the
reported number of juveniles in private
facilities is understated. The population
counts presented here do not match
the data reported in other analyses of
OJJDP’s CJRP data due to the various
adjustments in this analysis.

4. Adjustments were based on the assumption
that the 1997 population represents
an accurate count of juveniles in
custody in both private and public facilities.
The ratio of the private to public
populations in 1997 was applied to the
1993 and 1995 reported counts of juveniles
in public facilities to adjust the number
of youth in private facilities in those
years.

5. The number of “admissions” into residential
facilities is required to compute
the relative rate of placement for any
given year. A count of admissions is also
essential input for projecting future juvenile
commitment populations. Data on
true admissions, however, are not available
from any national data collection
program (e.g., the National Juvenile Court
Data Archive, the Census of Juveniles in
Residential Placement, or the Children in
Custody census). The National Juvenile
Court Data Archive, however, can provide
data on the number of adjudicated juvenile
court cases resulting in commitment
to residential placement during each year
of the analysis. These data are used as a
proxy for the number of “admissions” into
residential placement.

6. Transition probabilities were calculated
for 1993 and 1997 on an offense-specific
basis. The overall change in the commitment
population between 1993 and 1997
was then decomposed into the changes in
these transitions from stage to stage during
the period.